This invention relates to an apparatus and method for remotely powering a data acquisition or utilization device.
FIG. 1 shows a data terminus 11 and a data acquisition and utilization device 13. By way of example, let us consider the case in which the data acquisition and utilization device is a security camera for monitoring activity in the vicinity of the camera and the data terminus is at a central monitoring station. The central monitoring station transmits control data for controlling operation of the camera over an Ethernet connection, and the security camera transmits video data to the central monitoring station over the same Ethernet connection.
The Ethernet connection is implemented using the conventional PoE (power over Ethernet) physical infrastructure, including at least four UTPs, and in which the data terminus 11 is a power sourcing equipment and the security camera 13 is a powered device. The power sourcing equipment includes a DC power supply 12 and a data transceiver 14. The power supply 12 applies a DC voltage between two of the UTPs in known fashion. The security camera 13 includes a power supply (not separately shown) that recovers the DC power from the signals received over the Ethernet connection and employs the DC power to operate the camera.
Conventional PoE standards and practices limit the DC voltage that can be applied to the Ethernet connection by the power sourcing equipment 11 to about 48 volts and this limits the distance of the camera from the central monitoring station to about 100 meters. However, in many cases it would be desirable that the camera be at least 1000 meters from the central monitoring station.